Carbonated beverages are available in two and three liter plastic bottles. Typically these bottles are stored upright in a refrigerator and when their contents are withdrawn, a cap is removed from the bottle and the liquid contained therein is poured out. Although it is economical to purchase beverages in these large bottles, their size makes pouring awkward, especially for children. Therefore, it is desired that a replacement cap for the bottle be provided which has an integral sealable mechanism for dispensing the liquid without having to remove the cap. This would allow the bottle to be stored on its side in a refrigerator and the dispenser cap simply activated to empty the contents of the bottle as desired. For this purpose sealable spigots have been devised for these containers.
When liquid is poured from a bottle, the liquid will gurgle as air is forced to enter the opening against the liquid flow in order to replace the liquid that is flowing out of the bottle. The gurgling of the flow often results in a splashing of the liquid into the container into which it is being drawn. The same gurgling occurs if a simple spigot is used in a bottle that is on its side in a refrigerator. In addition if the contents of the bottle is a carbonated beverage the liquid will be under pressure due to the escape of the carbonated gas from the beverage into the atmosphere within the bottle. As a result when the spigot is first opened the liquid may tend to spurt out due to the gas pressure.
It is therefore desirable to provide a liquid dispenser with a passage which allows air to enter the bottle without producing a gurgling action. It is further desirable to release the gas pressure within the bottle prior to the flow of the liquid through the dispenser.